Screw driving means



March 14, 1939- RA E. sci-HEBER 2,150,343

SCREW DRIVING MEANS Filed oct. 9, 193e El. EE.. -I//vy /2 ru 4 l V74 ATTORNEYS.

Patented Mar. 14, 1939 UNITED sTATEs PATENT oi-Fl'cE- 2,150,343 soasw parvum mints athens. ssaiebeanetroiz, man. Anuman omha- 9, 1m, serai N. 1mm

l z clam. (ci. 14s-sz) The invention relates to an attachment for a conventional drill press adapted to be used for driving screws and the like.

It is the general object of the invention to pro- 5 vide an attachment for a conventional drill pr'ess ofthe type in which the drill spindle is moved axially by a manual lever, which attachment may be'utilized for driving screws and is characterized by the fact that the twisting force `exerted by the screw driving element is limited in accordance with the axial pressure exerted by the drill spindie in order that the maximum twisting forcema be readily controlled by the operator.

A further object of the invention is to provide an attachment of the type mentioned wherein the screw driving element is driven through a friction clutch which is permitted to slip when the screw is driven home with the desired degree of tightness.

A further object of the invention is to provide an improved attachment Vof the type described wherein relatively few simple parts are required, which parts are releasably held in assembled position by a resilient retaining device in order that the attachment may be readily disassembled for repair, replacement, or inspection.

Another object of the invention is to provide a device of the character described embodying an improved means for guiding the screw driving element with respect to the screw head to prevent the screw driven element from slipping out of engagement with the head and mai-ring the work or interrupting the driving operation.

Other objects and advantages of the invention 3;, will become apparent from the following specification, the accompanying drawing and appended claims.

In the drawing, wherein like'numerals are ap 4 plied to like parts in the several views:

40 Figure 1 is a fragmentary illustration of a drill press showing the drill spindle, the supporting table and the attachment constituting the invention applied thereto;

Fig. 2 is an enlarged axial section of the attachment shown in Fig. i;

Fig. 3 is a transverse section taken on the line 2 3 of Fig. 2; A

Fig. 4 is a transverse section taken on the line 4-4 of Fig 2; and I v Iilg. 5 shows a modified form of a screw driven head adapted for use on hexagonal headed screws.

Referring to Fig. l, there isshown the lower end of a drill spindle i of a conventional drill pres. having a work supporting bed 2. The details r-f the drill press are not shown inasmuch as they are conventional, but preferably the press is of the type having a hand operated lever for feeding the drill spindle axially towards the work. As shown in Fig. 1, the screw driving attachment 3 constituting the present invention is attached l to the drill spindle and is adapted to drive a screw into a pair of members I and I which it is desired to secure together.

The screw driving attachment comprises a driven element Il having a tapered shank i2, preferably of the conventional Morse taper, in order that it may be inserted into the usual opening in the lower end of the drill spindle I. The extremity of the tapered portion I2 of the driven element is flattened at I4 and extends into a suitable cooperating slot in the drill spindle in order to provide a driving connection. At the lower end of the tapered portion I2 the-driven element is provided with a radially extending aange ls adapted to constitute one o f a pauor an cooperating friction clutch elements; and the periphery of the radial flange It is provided with an axially directed ange I2 adapted to house 4 the clutch assembly. If desired. a suitable clutch facing material 2l may be secured in any desired 25 manner to the under face of the flange I6 within the confines of the flange I2. Any desired material may be used for the facing 20, but` ordinary graphite gasket material has been found satisfactory. 30 Y Below the flange IG, the driven element is provided with a downwardly extending cylindrical extension 22 having an axial bore. for a purpose to be described hereinafter.

A coupling member 2C having an axially ex- 35 tending bore 28 is journaled on the lower extension 22 of the driven element; and the member is provided with a radially extending flange 30 adapted to frictionally engage the clutch facing material 2l -to provide a friction drive between 4o the driven element and the coupling member. The driven element and coupling member are releasably held against axial displacement by means of a split spring retaining ring 32 seated within a groove on the inner face of flange I8. 45 'I'his spring prevents accidental withdrawal of the coupling member from the driven element but may be readily removed when it is desired to disassemble these members.

A screw driving element l. provided with a reso duced shank portion 2l is inserted into a suitable opening in coupling member 2i until the vreduced shank 22 is journaled within the bore 24 of extension 22 of the driven element. The screw driving element below the shank portion 2l is enlarged in diameter as at 4l, and the upper extremity of this portion oi enlarged diameter is provided with oppositely disposed iiats 42, as best shown in Figs. 2 and 3. These iiats are adapted to i'it cooperating inward projections 44 on the walls oi' the coupling member Il in order that the Vcoupling member may drive the screw driving element. 'I'he coupling member 2l is provided below the projections 44 with a counterbore adapted to Ireceive the enlarged cylindrical por-i tion oi the screw driving element; and a retaining spring 4I positioned within cooperating grooves I and 52 in the coupling member and screw driving element respectivelyoperates to relcasably retainthe screw driving element in assembled relation with respect to the coupling member.

Retaining spring 48 is split and the upper side wall of groove 52 is conical in form-in order that the spring may be cammed outwardly into groove 5I!l when the screw driving element i's withdrawn from the coupling member.

Means are provided for guiding the screw driving element into engagement with the head of the screw and for holding it in driving relation with respect thereto during the screw driving operation. Ihis means comprises a cylindrical guide member M, having a bore I6 adapted to receive the lower end oi the screw driving element, and an enlarged counterbore $8 in itsupper end. The open end ot the counterbore ls is closed by means oi a cap member 80 which is press fitted into the open upper end of the cylindrical guide member M and is provided with an opening adapted to slidably receive the main body of the screw driving element. A split spring retaining ring 82 is carried by the screw driving element within a suitable groove M, the lower side wall of which is conical in form in order that the yspring 61 may be cammed outwardly when it engages theunderside of cap Il to permit the complete withdrawal of the screw driving element from guide member Il. 'Ihis spring element, however, normally retains the guide member on the screwdriving element and prevents accidental displacement thereof.

Journaled on the screw driving element within the counterbore 58 and below groove 6l is a ring G8 provided with an internal shoulder II adapted to engage the spring ring 62; and a coil spring surrounding the screw driving element within the counterbore 58 and bears against the ring-V 66-and the shoulder 12 at the lower end of the counterbore 58, thus normally urging the guide member il downwardly with respect to the screw driving element.

While, as shown in Fig. 2, the lower extremity oi' the screw driving element is of reduced dialin-4 eter to iit the bore 56, it will be understood that the diameter ci' this portion of the screw driving element and bore 56 may be selected as desired in accordance with the size oi the screw which is being driven. It is contemplated that with the attachment a plurality of screw driving elements and associate guiding members will be provided, each assembly of screw driving element and guiding member being designed to iit a screw of a different size. It will be apparent, therefore, that each of the assemblies will be identical to each other except with respect to the diameter of the bore 56 in the guiding member 54 and the diameter of the lower end of the screw driving element which ts bore 56, these two dimensions being varied in the several units in accordance with the size of the screw to be driven.

It is apparent from the above that when the screw driven element is not in engagement with thehead oi a screw the guiding member Il occupies the position indicated in dotted lines at Il in Fig. 2, being urged into that position by means ot the spring 1l. Accordingly. as. the attachment is advanced towards the head of the screw desired to be driven, the guiding member Il lwill project in advance o! the screw driving element and will engage the head of the screw prior to the engagement by the screw driving element proper. The lower end of the guiding member s4 is provided with a conical surface 1| adapted to engage the screw head and center the same with respect to the screw driving element. Following engagement of the screw by member I4 the attachment is further advanced towards the head of the screw until the lower end o! the screw driving element, which is flattened at Il in the usual manner, enters the slot provided in the head of the screw. In addition to the above described function, guiding element Il operates to retain the screw driving element in operative engagement with the head of the screw during driving thereofand thereby prevents in- Jury to the member l or interruption o! the screw driving operation.

It will be observed that the twisting force exerted is transmitted entirely through the tric- 4tional engagement between clutch elements I6 and il, and that. therefore. the twisting force is directly proportional to the axial pressure exerted upon the screw head. vSince this axial pressure is under the control of the operator through the conventional axial feed handle for the drill spindie, the operator may readily control the amoimt of twisting force and limit such torce to that required. When the screw is driven home the i'rictional surfaces II and Il will simply slide relative to each other without any increase in torce exerted upon the head oi the screw.

In Fig. 5 is shown a screw driving element adapted for use in connection with screws having square or hexagonal heads in which no slots are provided. This screw driving element is provided with a shank Si similar to shank. of the element shown in Fig. 2, and is also provided with iiats I4 and groove 92 similar to ilats 42 and groove l2 in the form shown in Fig. 2, this structure being identical to that in the previously described modiilcation in order that this de'- vice may-be used in connection with the driving element and coupling member assembly previously described. The remainder ofthe element, however, is diii'ernt in that it comprises a. simple hexagonal shank Il upon which is carried a conet 91 is removable from the shank 90 in order that various sizes of sockets may be utilized. Accordingly, the shank Il is provided with peened out projections Il adapted to limit movement of the socket 81 onto the shank, and a conventional spring pressed ball il! is utilized for frictlonally holding the socket against accidental displacement. It will be observed in this form that since socket member 91 encloses the screw there is no necessity of providing a guiding member as in the structure previously described. In other respects operation of this form of the invention is similar to that described in connection with that described in Fig. 2.

It will be observed that in accordance with the present invention that there is provided an exceedingly simple and inexpensive attachment for a drill press which will adapt it for driving ventional socket wrench I1. Preferably the sock- :,icogsas screws, and which attachment may be readily disassembled for repair, replacement or inspection.

While only two forms of the invention have been disclosed, it is apparent that others are available within the spirit of the invention and within the scope of the appended claims.

What is claimed is:

1. An attachment for a drill press having a spindle comprising a driving element adapted to be operatively connected to'and rotated by said spindle, said driving element having an outwardly extending iiange and an axially directed cylindrical guiding portion. a driven element journaled on said guiding portion and having an outwardly extending ange adapted to make a frictional connection with the outwardly extending flange on the driving element, cooperating means on said outwardly extending ilanges for limiting the axial separation thereof, said driven element having an. opening for the reception of the shank oi a twisting tool to be driven thereby, and said' axially directed cylindrical guiding portion oi the driving element having an axially directed bore in -alignment with said opening in the driven element whereby the shank oi' said twisting tool will extend into and be guidedby said bore.

2. An attachment for a drill press having a spindle comprising a driving element adapted to be operatively connected to and rotated by said spindle, said driving element having a radially extending flange provided with a cylindrical axially directed marginal flange, a driven element rotatably carried by said driving element and having a radially extending flange adapted to makea frictional connection with the radially extending flange on the driving element. an internal groove in said axially directed marginal flange, a removable resilient snap ring seated in said groove and adapted to engage the radially extending flange on the driven element to prevent axial separation of said elements, and means on said driven element for receiving a twisting tool.

ROBERT E. SCHIEBER. 

